/Engine/Source/Editor/SequencerCore/Public/MVVM/Views/SOutlinerView.h
Set the item's expansion state, including all of its children
void ExpandCollapseNode ( [TViewModelPtr](API\Editor\SequencerCore\TViewModelPtr)< [IOutlinerExtension](API\Editor\SequencerCore\MVVM\Extensions\IOutlinerExtension) > InDataModel, bool bExpansionState, [ETreeRecursion](API\Editor\SequencerCore\MVVM\Views\UE__Sequencer__ETreeRecursion) Recursion )